Sealed intermittent coater



Jan. 2, 1968 R. NUG ARUS 3,360,900

SEALED INTERMITTENT COATER 7 Filed May 13, 1965 2 Sheets-Sheet l 7 EN gW Kw ///////////ff/////// ////1///////////////A FIGQ l INVENTOR ANTHONYR. NUGARUS 1 3 WW/M*M ATTORNEYS Jan. 2, 1968 A R. NUGARUS SEALEDINTERMITTENT COATER Filed May 13, 1965 2 Sheets-Sheet 2 ATTORNEYS UnitedStates Patent 3,360,900 SEALED INTERNHTTENT COATER Anthony R. Nugarus,Chicago, IlL, assignor to Crompton & Knowles Corporation, Worcester,Mass, at corporation of Massachusetts Filed' May 13, 1965, Ser. No.455,568 15 Claims. (Cl. 53140) ABSTRACT OF THE DISCLOSURE A sealedintermittent coater for coating articles including a conveyer forcarrying articles through a coating station and a nozzle at the coatingstation for directing a sheet of coating material toward the articles,and means responsive to the movement of articles through the coatingstation for controlling the discharge of coating material from thenozzle.

This invention relates in general to a coating machine, and moreparticularly to a sealed intermittent coater for coating articles, andstill more particularly to an apparatus for applying a coating ofprotective material onto goods and articles, both edibles andnon-edibles, to package same.

With the advent of hot melt plastics and films, it has been desired toprovide an economically manufactured machine for economically andefficiently applying acoating of a hot melt plastic to goods andarticles for packaging same. The hot melt plastics include those thatare liquid at elevated temperatures and solid or rigid at roomtemperatures. For example, one plastic suitable might have anapplicating temperature of between 175 F. and 350 F. where it would bein liquid form and easily applicable by a nozzle arrangement, andthereafter solidify or n'gidify at normal room temperature. Moreover,some of these plastics decompose or deteriorate rapidly when in liquidform and exposed to ambient air. Therefore, difiiculty is encountered incoating with the heretofore available coating machinery.

It is therefore an object of the present invention to obviate the aboveidentified difiiculties and to provide a machine for coating articleseconomically and efiiciently with hot melt materials.

Another object of this invention is in the provision of a coatingmachine for coating articles and goods with hot melt materials that iscapable of maintaining the coating material while in liquid formprotected against the ambient air, and is capable of being easily andinexpensively manufactured.

Still another object of this invention is to provide a new and improvedcoating machine capable of giving intermittent coating operations.

A further object of this invention resides in the provision of a coatingmachine including a conveyer for passing articles through a coatingstation, one or more nozzles for discharging one or more sheets or filmsof coating material onto the article as it passes through the station,and means responsive to the movement of the article into and out of thecoating station for controlling the sheets or films of materialemanating from the nozzles.

Other objects, features and advantages of the invention will be apparentfrom the following detailed disclosure, taken in conjunction with theaccompanying sheets of drawings, wherein like reference numerals referto like parts, in which:

FIG. 1 is a diagrammatic view of one form of coating machine accordingto the present invention and showing a transverse sectional view takenthrough the article carrying conveyer;

FIG. 2 is a somewhat diagrammatic and sectional side 3,360,900 PatentedJan. 2, 1 368 1 elevational view of the conveyer and illustrating themanveyer;

FIG. 5 is a view similar to FIG. 4 but illustrating the use of threenozzles for coating an article moving through the coating zone;

FIG. 6 is a view similar to FIG. 5 but illustrating a single nozzle forcoating only the top side of an article moving through the coating zone;

FIG. 7 is a view similar to FIG. 5 and illustrating the use of a singlecoating nozzle for coating an irregularly shaped article on a packagingboard as it moves through 1 the coating zone;

FIG. 8 is a diagrammatic view of an alternate arrangement forcontrolling the operation of the coating nozzles in the coating zone;and

FIG. 9 is a diagrammatic perspective view, somewhat I fragmentary,illustrating the use of a pair of endless conveying members in place ofa single conveying member for use in the coating machine of the presentinvention.

Referring now to the drawings, the coating machine of the presentinvention illustrated in FIGS. 13 includes generally a conveyer 10 forreceiving articles 11 thereon to transport same through a coatingstation arranged below a coating nozzle 12. The conveyer as illustratedshows a solid or closed surface upon which the articles 11 aresupported, but it should be appreciated that this surface may beforaminous, defined by a plurality of moving chains or cables, or of anyother suitable type. The conveyer may be endless or reciprocating,depending upon the desires of the user, so long as it serves to advancethe articles through the coating station below the coating nozzle 12. Itshould also be appreciated that the coating nozzle 12 may be of anydesired type, but preferably one that will define a sheet or film ofcoating material that is capable of covering all or any desired part ofan article that is advanced by the conveyer to the coating station. Inthe illustrated embodiment, the articles 11 are mounted on a tray orplate 13 and the article is thereafter anchored to this tray or plate bythe coating material which may also strike the areas of the tray outwardof the article. The packaging according to the invention could take theplace of the well known blister or skin-pack packaging in the industry.

The discharge nozzle 12 is supplied with heated plastic material from areservoir or-tank 14 having a source of coating material 15 therein influid and heated condition. The reservoir 14 is jacketed to permit it tobe efficiently and adequately heated for maintaining the plastic in liquid form. Inasmuch as some plastics decompose or deteriorate while inliquid form and exposed to the ambient air, a cover 16 is provided toclose the reservoir and seal same from the outside air. Suitablefasteners 17 may be provided for effecting the seal. In order to providea more perfect atmosphere within the reservoir, a fitting 18 having avalve 19 associated therewith may be arranged to allow the withdrawal ofany air existing within the reservoir when it is initially closed and toreplace the air with an inert gas if desired.

An outlet 20 is provided at the bottom of the reservoir and connected toan inlet 21 of a suitable positive displacement pump 22. Preferably, thepump may be of the well known screw type. The pump 22 includes an outlet23 connected to a line 24 that leads to the discharge nozzle 12. Apremelter and tfeeder 31 may be provided to replenish the supply ofcoating material in the reservoir 14. A solenoid operated valve 25 isprovided ahead of the nozzle 12 to quickly control the nozzle between onand oil positions. A pressure regulating valve 26 is provided ahead ofthe solenoid operated valve 25 to control the pressure at the nozzle 12regardless of the pressure generated by the pump 22. A line 27 connectsinto the line 24 ahead of the control valve 26 and leads to a returninlet 28 in the reservoir 14. A pressure relief valve 29 is provided inthe by-pass line 27 to allow the coating material pumped into the line24 by the pump 22 to return to the reservoir when a predeterminedpressure is reached, and especially in the event that the nozzle 12 isin off position. The valve 29 may be adjustable if desired.

The solenoid operated valve 25 is controlled by a photoelectric device30 that detects movement of articles into and out of the coatingstation, whereby upon detecting the presence of an article in thecoating station will cause the solenoid operated valve 25 to open topermit the nozzle 12 to discharge a sheet or film of coating material.And upon detecting the article leaving the coating station or zone, thephotoelectric device 30 will cause the solenoid operated valve 25 toclose and thereby preclude the continuous operation of the nozzle andwastage of coating material. Thus, the nozzle 12 is operated only whenan article is in the coating station or zone, and when the valve 25 isclosed, the pressure in the line will build up and cause the pressurerelief valve 29 to open and return the coating material to the reservoir14. If desired, the lines 24 and 27 may be jacketed to provide heat andassure the maintaining of the coating material at a suitabletemperature. It should also be appreciated that the present machine maybe employed for coating of materials wherein the coating material neednot be heated. Typical of the type of non-heated materials would belacquers, enamels, and edible coatings such as starches, proteins andsugars. The nozzle and coating station may be enclosed in a heatedcabinet to facilitate the application of coating material if desired orneeded in a particular installation.

Referring particularly to FIG. 2, it is noted that the article 11a hasbeen coated while the article 11b is entering the coating zone orstation, and the article 110 follows behind the article 11b.

Referring now to FIG. 4, the coating machine of the present invention isillustrated wherein a pair of coating nozzles 32 and 33 are employed inthe coating zone to coat all six sides of the article 34 passing throughthe coating zone on the conveyer belt 10. The nozzle 32 would bepositioned to coat the front side 34a, the side 34b and the top side34c, while the coating nozzle 33 would be arranged to coat the side 34dand the back side 34a. of the article.

The nozzle arrangement of FIG. illustrates the use of three coatingnozzles 35, 36 and 37 for coating the six exposed sides of the article38. In this arrangement, the nozzle 35 is arranged to coat the frontside 35a and the adjacent side 35b, while the upper nozzle 36 ispositioned to coat only the top side 350. And the other coating nozzle37, positioned opposite the nozzle 35, is arranged to coat the side 35dand the back side 35c.

In the arrangement illustrated in FIG. 6, a single nozzle 39 is arrangedto coat only the top side 40a of the article 40. In this embodiment, itwould only be desirable to apply a coating to the top side of thearticle.

FIG. 7 illustrates the use of the nozzle arrangement in accordance withFIG. 6, wherein the single nozzle 39 is employed to package anirregularly shaped article 41, in this case a small toy automobile, ontoa cardboard tray 42 by applying a thin film 43 of a desired thicknessover the article 41 and across the top surface of the cardboard tray 42,wherein the film 43 is transparent and will ad- "here to the cardboardtray 42 to secure the article 41 thereto in package form. Such a packagesimulates a skin-pack or blister package and may thereafter permitshelving of the articles without subjecting them to the ambient air sothat they may be preserved longer. By opening of the film, the articlecan be easily removed.

From the embodiments shown in FIGS. 47, it can readily be appreciatedthat any desired number of nozzles can be employed in the presentinvention, all of which may be connected to the solenoid operated valvefor obtaining intermittent coating operation. Moreover, it can beappreciated that if the nozzles are so spaced in the coating zone, theymay be individually triggered on and off to give the desired coatingoperation for the articles passing through the zone. The speed of theconveyer may be between 50 and 500 feet per minute, while the pressureof the coating material emanating from the nozzle may vary between 100and 2,000 pounds per square inch. Further, the temperature of the heatedcoating material may vary between 100 and 500 F., while the viscosity ofthe material may vary from between 50 and 60,000 centiposes. Examples ofheated coating materials are thermaplastic coatings, such as polyamides,polyolefins, cellulosics and edibles such as chocolate.

A diagrammatic showing of an alternate control system for opening andclosing the nozzle or nozzles in the coating zone is shown in FIG. 8wherein a signal from a photoelectric cell 44 that detects the movementof an article into the coating zone is amplified by an amplifier 45which thereafter triggers an electronic timer 46 that maintains thesolenoid valve 47 open for a predetermined period of time. The solenoidvalve 47 would then control the coating material being fed to the nozzleor nozzles in the coating zone.

While it has been above mentioned that the conveyor may take the form ofa single belt as shown in the drawings in FIGS. 1-7, or the form of aplurality of belts or chains, a clear example of the latter form isillustrated in FIG. 9, wherein a pair of synchronized endless belts 48and 49 are employed in place of a single belt. The belts 48 and 4-9 arespaced apart thereby providing a space between them so that theunderside of a cardboard tray 50 having an article 51 thereon can beeasily lifted off the belts at the end of the conveyor run. Of course,the belts 48 and 49 may be chains or cables if so desired.

It will be understood that modifications and variations may be efiectedwithout departing from the scope of the novel concepts of the presentinvention, but it is understood that this application is to be limitedonly by the scope of the appended claims.

The invention is hereby claimed as follows:

1. A machine for applying a coating of material to articles comprising,a conveyor for carrying said articles through a coating station, anozzle arranged to direct a sheet of coating material toward saidarticles as they pass through the coating station, -a reservoir forholding a supply of coating material, a pump for pumping the coatingmaterial to the nozzle and forcing the material through the nozzle underhigh pressure, a valve ahead of the nozzle, means for quickly operatingthe valve between open and closed positions, means responsive tomovement of the articles into and out of the coating station for openingand closing said valve, and means bypassing said valve to return thematerial to the reservoir when the valve is closed.

2. A machine for applying a coating of material to articles comprising,a conveyor for carrying said articles through a coating station, anozzle arranged to direct a sheet of coating material toward saidarticles as they pass through the coating station, a reservoir forholding a supply of coating material, a pump for pumping the coatingmaterial to the nozzle and forcing the material through the nozzle underhigh pressure, a solenoid operated Valve ahead of the nozzle, meansresponsive to movement of the articles into and out ofthe coatingstation for opening and closing said valve, and means bypassing saidvalve to return the material to the reservoir when the valve is closed.

3. A machine for applying a coating of material to articles comprising,a conveyor for carrying said articles through a coating station, anozzle arranged to direct a sheet of coating material toward saidarticles as they pass through the coating station, a reservoir forholding a supply of coating material, a pump for pumping the coatingmaterial to the nozzle and forcing the material through the nozzle underhigh pressure, a solenoid operated valve ahead of the nozzle, meansresponsive to movement of the articles into and out of the coatingstation for opening and closing said valve, and a pressure responsivebypass line ahead of said valve to return the material to the reservoirwhen a predetermined pressure is detected.

4. A machine for applying a coating of material to articles wherein thematerial is liquid at elevated temperatures and solid at roomtemperatures, said machine comprising, a conveyor for supportingarticles thereon and advancing same through a coating zone, a nozzlepositioned adjacent the conveyor for discharging a continuous sheet ofcoating material into the coating zone, a reservoir for holding a supplyof coating material, means for heating the reservoir to maintain thecoating material in liquid form, a feed line extending from thereservoir to the nozzle, a pump in said feed line for pumping the liquidto the nozzle under pressure, a control valve between the pump andnozzle operable between open and closed positions, a return lineextending from said feed line to said reservoir and communicating withthe feed line between the valve and pump, a pressure relief valve insaid return line, and means detecting the presence and absence of anarticle in the coating zone to open and close said control valve.

5. A machine for applying a coating of material to articles wherein thematerial is liquid at elevated temperatures and solid at roomtemperatures, said machine comprising, a conveyor for supportingarticles thereon and advancing same through a coating zone, a nozzlepositioned adjacent the conveyor for discharging a continuous sheet ofcoating material into the coating zone, a reservoir for holding a supplyof coating material, means for heating the reservoir to maintain thecoating material in liquid form, a feed line extending from thereservoir to the nozzle, a positive displacement pump in said feed linefor pumping the liquid to the nozzle under pressure, a control valve insaid feed line between said nozzle and pump, an actuator for actuatingsaid control valve between open and closed positions, a return linebetween said feed line and said reservoir and connected to said feedline between said control valve and said pump, a pressure relief valvein said return line, and means detecting the presence and absence of anarticle in the coating zone to operate said actuator so that the controlvalve is open when an article is passing through the coating zone andotherwise closed.

6. A machine for applying a coating of material to articles wherein thematerial is liquid at elevated temperatures and solid at roomtemperatures, said machine comprising, a conveyer for supportingarticles thereon and advancing same through a coating zone, a nozzlepositioned adjacent the conveyer for discharging a continuous sheet ofcoating material into the coating zone, a reservoir for holding a supplyof coating material, means for heating the reservoir to maintain thecoating material in liquid form, a feed line extending from thereservoir to the nozzle, a positive displacement pump in said feed linefor pumping the liquid to the nozzle under pressure, a control valve insaid feed line between said nozzle and pump, a solenoid for actuatingsaid control valve between open and closed positions, a return linebetween said feed line and said reservoir and connected to said feedline between said control valve and said pump, a pressure relief valvein said return line, and means detecting the presence 6 and absence ofan article in the coating zone to operate said solenoid so that thecontrol valve is open when an article is passing through the coatingzone and otherwise closed.

7. A machine for applying a coating of material to articles wherein thematerial is liquid at elevated temperatures and solid at roomtemperatures, said machine comprising, a conveyer for supportingarticles thereon and advancing same through a coating zone, a nozzlepositioned adjacent the conveyer for discharging a continuous sheet ofcoating material into the coating zone, a reservoir for holding a supplyof coating material, means for heating the reservoir to maintain thecoating material in liquid form, a feed line extending from thereservoir to the nozzle, a positive displacement pump in said feed linefor pumping the liquid to the nozzle under pressure, a control valve insaid feed line between said nozzle and pump, a solenoid for actuatingsaid control valve between open and closed positions, a return linebetween said feed line and said reservoir and connected to said feedline between said control valve and said pump, a pressure relief valvein said return line, and means detecting the presence and absence of anarticle in the coating zone to operate said solenoid so that the controlvalve is open when an article is passing through the coating zone andotherwise closed, said means including a photoelectric device.

8. A machine for applying a coating of material to articles wherein thematerial is liqiud at elevated temperatures and solid at roomtemperatures, said machine comprising, a conveyer for supportingarticles thereon and advancing same through a coating zone, a nozzlepositioned adjacent the conveyer for discharging a continuous sheet ofcoating material into the coating zone, a reservoir for holding a supplyof coating material, means for heating the reservoir to maintain thecoating material in liquid form, a feed line extending from thereservoir to the nozzle, a positive displacement pump in said feed linefor pumping the liquid to the nozzle under pressure, a control valve insaid feed line between said nozzle and pump, an actuator for actuatingsaid control valve between open and closed positions, a return linebetween said feed line and said reservoir and connected to said feedline between said control valve and said pump, a pressure relief valvein said return line, means detecting the presence and absence of anarticle in the coating zone to operate said actuator so that the controlvalve is open when an article is passing through the coating zone andotherwise closed, and a pressure regulating valve between said controlvalve and said pump to regulate the nozzle discharge pressure.

9. A machine for applying a coating of material to articles wherein thematerial is liquid at elevated temperatures and solid at roomtemperatures, said machine comprising, a conveyer for supportingarticles thereon and advancing same through a coating zone, a nozzlepositioned adjacent the conveyer for discharging a continuous sheet ofcoating material into the coating zone, a reservoir for holding a supplyof coating material, means for heating the reservoir to maintain thecoating material in liquid form, a feed line extending from thereservoir to the nozzle, a positive displacement pump in said feed linefor pumping the liquid to the nozzle under pressure, a control valve insaid feed line between said nozzle and pump, an actuator for actuatingsaid control valve between open and closed positions, a return linebetween said feed line and said reservoir and connected to said feedline between said control valve and said pump, a pressure relief valvein said return line, means detecting the presence and absence of anarticle in the coating zone to operate said actuator so that the controlvalve is open when an article is passing through the coating zone andotherwise closed, and means for heating said feed and return lines totemperatures above the melting temperature of said coating material.

10. A machine for applying a coating of material to articles wherein thematerial is liquid at elevated temperatures and solid at roomtemperatures, said machine comprising, a conveyer for supportingarticles thereon and advancing same through a coating zone, a nozzlepositioned adjacent the conveyer for discharging a continuous sheet ofcoating material into the coating zone, a reservoir for holding a supplyof coating material, means for heating the reservoir to maintain thecoating material in liquid form, a feed line extending from thereservoir to the nozzle, a positive displacement pump in said feed linefor pumping the liquid to the nozzle under pressure, a control valve insaid feed line between said nozzle and pump, an actuator for actuatingsaid control valve between open and closed positions, a return linebetween said feed line and said reservoir and connected to said feedline between said control valve and said pump, a pressure relief valvein said return line, means detecting the presence and absence of anarticle in the coating zone to operate said actuator so that the controlvalve is open when an article is passing through the coating zone andotherwise closed, and means for closing said reservoir in sealedrelation to the ambient air.

11. A machine for applying a coating of material to articles comprising,a conveyer for carrying said articles through a coating station, anozzle arranged to direct a sheet of coating material toward saidarticles as they pass through the coating station, a reservoir forholding a sup ply of coating material, a pump for pumping the coatingmaterial to the nozzle and forcing the material through the nozzle underhigh pressure, a valve ahead of the nozzle, means for quickly operatingthe valve between open and closed positions, means responsive tomovement of the articles into and out of the coating station for openingand closing said valve, said movement responsive means including aphotoelectric device that operates to open said valve when detecting anarticle in the coating station, and means bypassing said valve to returnthe material to the reservoir when the valve is closed.

12. A machine for applying a coating of material to articles comprising,a conveyer for carrying said articles through a coating station, anozzle arranged to direct a sheet of coating material toward saidarticles as they pass through the coating station, a reservoir forholding a supply of coating material, a pump for pumping the coatingmaterial to the nozzle and forcing the material through the nozzle underhigh pressure, a valve ahead of the nozzle, means for quickly operatingthe valve between open and closed positions, means responsive tomovement of the articles into and out of the coating station for openingand closing said valve, said movement responsive means including aphotoelectric device and a timing device whereby the photoelectricdevice detects an article approaching the coating station and triggersthe timer which operates the valve in open position for a predeterminedperiod of time, and means bypassing said valve to return the material tothe reservoir when the valve is closed.

13. A machine for applying a coating of material to articles comprising,a conveyer for carrying said articles through a coating station, aplurality of nozzles arranged to direct a plurality of sheets of coatingmaterial toward said articles as they pass through the coating station,a reservoir for holding a supply of coating material, a pump for pumpingthe coating material to said nozzles and forcing the material throughsaid nozzles under high pressure, a valve ahead of said nozzles, meansfor quickly operating the valve between open and closed positions, means-responsive to movement of the articles into and out of the coatingstation for opening and closing said valve, and means bypassing saidvalve to return the material to the reservoir when the valve is closed.

14. The combination as defined in claim 13, wherein two nozzles areprovided.

15. The combination as defined in claim 13, wherein three nozzles areprovided.

References Cited UNITED STATES PATENTS 2,714,870 8/1955 Girando 1l8- 23,008,824 11/1961 Wallis.

3,008,836 11/1961 Wallis.

3,061,446 10/1962 Normanetal.

3,178,866 4/1965 Wallis 53-140 GRANVILLE Y, CUSTER, 111., PrimaryExaminer.

